This invention relates generally to fasteners and fastening techniques for fastening logs. More particularly, the present invention relates to fasteners and techniques for fastening together wood beams, landscape timbers and the logs of a log home.
Log homes which are manufactured from pre-shaped logs formed in an efficient, mass production process are now common-place. The pre-formed logs are transported to the building site, and the log home is constructed in a highly efficient process. The construction process conventionally involves fastening together the logs which form the walls of the home. Because the logs have a substantial thickness, typically on the order of 6 inches or more, and because over time there is ordinarily significant settling and displacement of the connected logs subsequent to construction, the fastening process is not entirely straightforward.
One wide spread conventional log fastening technique involves drilling a hole in the log that is to be secured on top of a bottom secured log. A counter-sink is also drilled. After the hole and counter-sink are formed, a large spiral nail or a common nail is driven through the hole into the bottom securing log, or a long screw is inserted through the pre-drilled hole and threaded into the bottom log. The fastener head is driven into the counter-sink. U.S. Pat. No. 5,400,845, assigned to the assignee of the subject application, discloses a self-drilling/tapping fastener which is driven through the log that is to be secured without pre-drilling a bore. In log construction a limited free movement of the logs must be accommodated since over the lifetime of the log home, the logs ordinarily will shrink and will also settle. In addition, the fastening technique must be accomplished without splitting the logs.